Reciprocating engine



3 1946. 1.. c. ROTTER ET AL RECIPROCATING ENGINE Original Filed 001;. 4,1945' I 5 Sheets-Shet l FIG. 3.

July 1946 TTER ET l. 2,404,315 I REQIPROCATING ENGINE 3 Shets-Sheet 2Original Filed Oct. 4, 1943 FIGZ.

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\IL I 39 'July 16, 1946. L. c. ROTTER ET AL 2,404,315

REOIPROGATING ENGINE OriginalFiled Oct. 4, 1945 s Sheets-Sheet s VPatented July 16, 1946 RECIPROCATING ENGINE Lutwin C. Rotter, Maplewood,and Victor G.

Klein, St. Louis, Mo., assignors to Lincoln Engineering Company, St.Louis, Mo., a corporation of Missouri Original application October 4,1943, Serial No.

504,852. Divided and this application December 11, 1944, Serial No.567,590

This invention relates to engines, and with v regard to certain morespecific features to reciprocating air engines for driving lubricantpumps and the like.

This invention is a division of the invention specified in our UnitedStates patentapplication Serial No. 504,852, filed October 4, 1943, forBeciprocating engine.

Among the several objects of the invention may be noted the provision ofa compactly formed lost-motion coupling between the main reciproeatingparts of an engine and its valve gear whereby with a fewer number ofparts the valve gear may be located so as to effect better distributionof air to the engine cylinder; the provision of an apparatus of theclass described which allows of a better distribution of wear betweenthe engine piston and its cylinder; and the provision of asimplifiedlonger wearing engine valve gear. Other objects will be inpart obvious and in part pointed out hereinafter. I f

The invention accordingly comprises the elements and combinations ofelements, features of construction, and arrangements of parts which willbe exemplified in the structures hereinafter described, and the scope ofthe application of which will be indicated in the following claims.

In the accompanying drawings, in which is illustrated one of variouspossible embodiments of the invention, Fig. l is a side elevation of anengine embodying the invention;

Fig. 2 is a cross section taken on line 2--2 of Fig. 1, parts beingshown in elevation;

Fig. 3 is a section taken on line 3--3 of Fig. 2 Fig. 4 is anenlarged-vertical section taken on line 44 of Fig, 2 showing certainparts overcentered upward; and, v

Fig. 5 is an enlarged horizontal section taken on line 5-5 of Fig. 4 butshowing parts in dead center position.

Similar reference characters indicate corresponding parts throughout theseveral views of the drawings.

In United States Patents 2,215,852 and 2,269,-

1942, respectively, are shown valve mechanisms and the air engines whichthey serve, upon which the present invention is an improvement; Thepresent invention is an improvement of that type I 423, dated September24, 1940, and January 13,

of valve gear and upon the location of it on the air engine cylinder.Instead of being at the end as in said patents, the valve gear is on theside of the cylinder. The valv gear itself is improved by providing abetter straight-line trip-shoe ac- 5 Claims. (Cl. 74-100) motionmechanisms, a laterally located lost-mo-.

Referring now more particularly to the drawings, numeral indicatesthecylinder of the engine,'numeral 3 is the piston on the piston rod 5,the latter passing through a packing gland I. A cylindric frame 9connects the cylinder I with the pumpv i. The rod 5 is directlyconnected to th'e rod l2 of the pump II for direct-connectedreciprocating driving purposes. The cylindric frame 9 is cut away asshown at l0 for access to parts to bedescribed. Other parts are extendedas shown at 23 to form a box-like enclosure for a linkage to bedescribed,

One side of the cylinder is provided, aS indicated at numerals I3 andI5, with inlet and exhaust ports with which a D-valv l1 cooperates. Incover I9 is the valve gear per se. The operating stem of the valve isshown at 2|. This stem 2| passes through a reciprocatin gland 5| and islocated at its opposite end in a bearing 53. In the bearing 53thestemcarries a sleeve 55attached to it by means of a pin 51. This forms ashoulder 53 for purposes which will appear.

Sliding on a reduced section 59 of stem 2| is a trip shoe 5|, By reasonof the upper shoulder 53 formed by a sleeve 55, and a lower shoulder 65,

the stem 2| has lost-motion engagement with respect to the trip shoe 3|whether the shoe be up or down. The trip shoe has end shoulders 61 and59 which provide lost-motion engagement between the shoe and the D-valvel1.

Extending from the trip shoe BI is a pin 1| which reaches through a forkor clevis 13 of a rocker 15. Within theclevis the pin 1| carries aroller 11. The roller 11 rolls on a vertical guide surface 18 whichforms part of a U-shaped mem- ,ber 19 bolted to the cover l9 asindicated at 8|. Guides are formed by the edges 83 of the member 19 andbya shoulder 850i the cover l9. These guides are for a sliding yoke 81which is pivoted at, to an air-tight plunger 9|. The plunger operates ina stufiing box 93 and carries an exteriorly extending tell-tale 95.

The rocker 15 is supported by (and slides in) out the plungervthelD-valve- [.1'. t leftward bias of the yoke 8''! (from plunger 9!)urges. the rocker 'further-counterclockwise. At

a fork 91 which has a pivot 99 in a bearing lill of the case l9. Beyondthe fork 91 the rocker 15 is made as a fork or clevis I03 for receivinga second roller I535. The clevis has extended ends I 81 movably engagingopposite faces of. the adjacent portionof the yoke 81. This guidesv therocker co-planar with the yoke.

The roller I05 contacts a driven face I 69 of the yoke 81 which althoughmovable is at all times parallel with face 18. Face 18 is turned intothe plane of the yoke (Figs. 4 and 5") Thus if the rocker is movedcounterclockwise: tFig. 4 the roller 11 will traverse face 18: androller I325. will traverse face I29, thus driving the yoke 81 to theright. This pulls in the plunger Hit.- The plunger is biased outward byair pressure carried within the cover [9. This pressure is supplied theair admitted from inlet opening Ill and which passes to the port l3 viathe -D-valve [1 which effects its proper distribution. Thus it will beseen that'the yoke 81 is normally biased to the left (Fig. 4.) by theair pressure tending to push When the rocker 15 rotatescounterclockwise, the yoke is pushed to the right. The yoke'reaches itsmaximum position toward the right. when the rocker 15 is abouthorizontal (seeFig. 5'). This is the dead-center position. Thereafterfurther movement of the rocker will cause the yoke to. urge it furtherin a counterclockwise direction. .Down to the dead-center position, thedescending rod 2| is responsible'for drawing down the pin, throughcooperation between the shoulders63" and 69.

Movementtoj dead-center position about takes up the lost-motion betweenthe trip shoe 6! and Then upon over-centering, the

this time the distance between shoulders 61 and 65 istraversed. Downwardmotion of pin TI' being atthis time unimpeded. This drives down thepin"1l,. trip shoe 6|. and D-valve [1. Thus the lost "motion betweenshoulders 61 and 55 is taken up after overcenteri-ng. The. air pressurein the cover is tending ;toforce the plunger 9l' out of gland-93 causesthe bias. Hence the D'-valve .IT is reset to introduce air above thepiston 3 when the piston has about reached its dotted line 4 betterbearing surfaces for the parts connected with the pin 1| and a longerlife. The device is simpler and easier to manufacture than that shown insaid Patent 2,215,852.

The stem 2| reaches into the enclosure 23, and underneath a removablecover l4: through an opening I6. In the enclosure is a pivot 25 for arocker 21. Pivot 25 is held in bearings 26. At the left (Fig. 2) therocker 21 is pivoted at a clevis 28 with a connecting link 29 (see pivot3|). The connecting link 29 is pivoted at 32 ina clevis 35 attached tothe rod. 2! by threading and a cotter key On th-e right hand side, therocker 21 is forked as indicated at 31' providing spaced fingers 39.

.Pre'sseda into each finger as of the fork 31 is a rounded hardened wearpin ll. Operating between the pins AI is a driving disc 43. Disc 43 iswelded to the piston rod 5. The frame 9 and the enclosure 23 aredesigned to fit. closely around the described linkage, including thedisc 43, exceptat opening I'D which is to permit access.

Operation not already described is as follows: Upon reciprocation, thedisc Mstrikesi first one 4! (solid lines, Fig. 2.), and then the other(dotted lines), with lost motions therebetween. The lost motion is of adegree adapted to'produce valve. over-centering snap action onlywhenever the piston 3 is near. the end of its stroke (see dotted linesin Fig. 2), thus making the engine! of the so-called' full-stroke type.

That is. there is no cut-off expansive event in the. work cycle of theengine cylinder.

Another advantage of the invention is that the connection between the.rocker 21 and the disc 43 is. such that the disc may rotate freely alongwith the piston 3 which is in the cylinder f, and also the piston rod 5in the packing 1, as well asthe plunger, of the. pump II in itscylinder. fThus scoring and localized wear is reduced in theseparts. Inother words, the reciprocating parts may rotate indifferently in- Vstead ofbeing confined topure axial movement.

In addition, the valve gear is placed closer to the point of airdelivery in the cylinder I, and there- V fore. the passages l3 and i5become much shortpos'itio'n shown in Fig.2. This reverses the piston 'fimovement, and through the valve driving mecha hisrn (to be described)ultimately reverses the.

movement-of the stem 2[ whereupon the above" described. action betweenstem 2| and shoe 5! is repeated'in reverse. 'The only difierence is thatthis time the lost-motion between the trip shoe .6 i the D-valve [1 isbelow the valve, and the lostmotion between the trip shoe and thestem 6|exists above between shoulders 69 and 63. In.

this case initial movement of the rocker 15 to dead center position isclockwise. This again forces the yoke 8Tto the right until dead-center Yis reached, whereupon" biasfof" the yoke forces the .rocker furtherclockwise so that snap-action occurs back to the position shown in Fig.4, thus the other hand, the latter being necessary for the subsequentdownward operation.

This valve gear has the substantial advantage overthose shown in saidPatent 2,269,423 in that there is no lateral rocking movement requiredof the pin H which in the present case simply trans lates in a straightline. This allows for arranging er. Consequently less friction restrictsflow of airand capacity is increased. At the same time the operatingparts are compactly arranged in a space which is closely surrounded byguarding frame portions which form the connection needed between theengine and pump parts.

It will be noted that the connecting. parts 9 between the engine and.pump forms a cylinder closely surrounding the'cylindric figure swept outin space by the reciprocating disc 43. f

In view of the above, it will be seen that the several objects of theinvention are achieved and v other advantageous results attained.

As manychanges could be made. in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a. limitingsense.

We claim:

I 1. Over-centering, Valve mechanism comprising a fixedf'guide, amovable guide moving lat-- ciprocating trip shoe pivotally attached nearone end of said rocker and movable along a line between the fixed guideand said pivoting means.

2. Over-centering valve mechanism comprising a straight fixed guide, astraight movable guide parallel thereto, means for biasing the movableguide at right angles toward the fixed guide, a rocker carrying near oneend means engaging and movable along the fixed guide and at the otherend means engageable and movable with the movable guide, pivoting meanssupporting said rocker for rotary and relative sliding movement, and areciprocating trip shoe pivotally attached near one end of said rockerand movable along a straight line parallel to the fixed guide andbetween it and said pivoting means.

3. Over-centering valve mechanism comprising a straight fixed guide, astraight movable guide parallel thereto, means for biasing the movableguide at right angles toward the fixed guide, a rocker carrying near oneend means engaging and movable along the fixed guide and at the otherend means engageable and movable with the movable guide, pivoting meanssupporting said rocker for rotary and relative sliding movement, and areciprocating trip shoe pivotally attached near one end of said rockerand movable along a straight line parallel to the fixed guide andbetween it and said pivoting means, said rocker and the engagementregions on the guides being in the same plane.

4. Snap-acting valve mechanism comprising a yoke, a yoke guide carryingsaid yoke for reciprocating movement, a fixed guide located inside ofthe yoke and in its plane of movement,

said second guide being at an angle to the firstmentioned guide, arocker forked at both ends and located within said yoke in the plane ofsaid fixed guide, a roller and a trip shoe pivoted int the fork of therocker adjacent to said fixed guide and movable in a direction to causesaid roller to traverse said fixed guide, a roller in the-fork at theother end of the rocker, a pivoting support for the rocker restrainingit to rotate with the pivoted means and to slide with respect to thesame during rotation, said yoke having a driven surface engaged by saidsecond-mentioned roller in the plane of the first-mentioned roller andthe said fixed guide.

5. Snap-acting valve mechanism comprising a yoke, a guide carrying saidyoke for reciprocating movement, a second guide located inside of theyoke and in its plane of movement, said second guide being at an angleto the first-mentioned guide, a rocker forked at both ends and locatedwithin said yoke, a roller and a trip shoe pivoted in the fork of therocker adjacent to said second guide and movable in a direction to causesaid roller to traverse said second guide, a roller in the clevis at theother end of the rocker, a pivoting support means for the rockerrestraining it to rotate with the pivoting means and to traverse thesame during rotation, said yoke having a driven surface engaged by saidsecondmentioned roller in the plane of the first-mentioned roller, andmeans biasing the yoke in a direction tending to force the rockerthrough the pivot means and toward said second-mentioned guide, saidlast-named means comprising an air operated plunger attached to theyoke.

LUTWIN C. ROTTER. VICTOR G. KLEIN.

